Islamist militants believed to be associated with the Nigerian terror group Boko Haram kidnapped the wife of a Cameroonian vice prime minister Sunday, in a worrying sign that the violence in northeastern Nigeria is spreading beyond its borders.

Shinzo Abe has spent much of his premiership trumpeting his achievements to foreigners, particularly those of Abenomics, his programme to kick-start the Japanese economy. But discontent is stirring at home.

A 15-year-old Japanese schoolgirl is being held in police custody after she admitted murdering her classmate and dismembering her body. The teenager, who cannot be identified for legal reasons, was arrested on Sunday after the body of 15-year-old Aiwa Matsuo was discovered in the city of Sasebo, in Japan's southwestern Nagasaki Prefecture.